For much of his more than six years as vice president, Joe Biden has been a willing caricature. He was the man who would chase the Islamic State to the "gates of hell." The man who said audibly into a live mic that the passage of Obamacare was a "big f****** deal." The man who playfully hit on senators' mothers.

When the often over-starched Obama administration needed a bluer collar, Mr. Biden got the call.

This weekend, however, Joe Biden was simply a father. And in that role, America got a glimpse into a different measure of the man.

For much of the past week, Biden's son, Beau, has been foremost in the minds of Americans. Widely hailed as a man of fierce integrity and tremendous promise, Beau Biden died from illness. At his funeral Saturday, the austerity of Joe Biden's boss faltered as Barack Obama wept for his friend and for a country's loss.

Into such eulogies, appropriately, Joe Biden has been inserted only in a supporting role. The devoted father. The conscientious former senator. The role model.

But in the fuller portrait of Beau Biden now being told, there is also a portrait of vice president himself. In the praise heaped on the son, there is no small reflection on the father.

Any political scientist will acknowledge that Joe Biden the politician has flaws as large as his outsized personality. But many on Capitol Hill will insist that the death of his son has only brought Biden the man into sharper relief as someone of enormous and genuine humanity.

In day-to-day Washington, this accounts for some good quotes and some even better gaffes. But, often unseen, it also accounts for a respect among his peers that outweighs either.

It is no coincidence that Biden was the man then-Senate minority leader Mitch McConnell (R) of Kentucky called in 2012 when he wanted to bargain with someone he trusted in the White House. The result was a deal to avoid the "fiscal cliff" – a steep rise in taxes for middle-class Americans.

Speaking at the time, Senator McConnell said: "Yesterday, after days of inaction, I came to the floor and noted we needed to act, but that I needed a dance partner. So I reached out to the vice president in an effort to get things done."

Yet perhaps the more remarkable measure of Biden's ability to gain the trust of those around him comes from within the White House itself. As McConnell had come to realize in 2012, this was not a White House inclined to trust easily. The Obama inner circle consisted of those who Mr. Obama had known from his days in Chicago and few else.

George E. Condon Jr. of the National Journal notes that Obama has lost control of his emotions publicly only three times as president. Once when grieving over the death of his grandmother. Once in the wake of the massacre at Sandy Hook Elementary School in Newtown, Conn. And Saturday.

White House aides have often tried to persuade reporters that this president and this vice president have a close bond. Just as often, reporters have voiced skepticism, aware of a two-century history of relationships ranging from open enmity to cool indifference between the men in the White House and their vice presidents. But more than six years into the presidency, it may be time to accept the claims as accurate. Even when Biden has misspoken or jumped the gun on positions, aides insist Obama harbored no anger at the vice president. "That's just Joe being Joe," they often say. "It's part of who he is."

They always appreciated Biden's loyalty and humanity. Saturday was a chance for the president to return that embrace. How he did it will be hard to forget.

To those who know him, Saturday was as much "Joe being Joe" as any full-blooded defense of American patriotism or ill-advised stumble into calling his term in the vice presidency a "s*** job."

In 2012, the Seattle Times's Michael Gerson wrote of these apparent contradictions: "What to make of Vice President Joe Biden? Sometimes he is gaffe-prone comic relief. Sometimes he is the possessor of the worst geopolitical judgment in Washington.... And sometimes he seems to be the last genuine human being in American politics."

At a time when politicians are cloistered and cosseted by political operatives, Biden's determination to be himself – no matter what the political wisdom – comes across as an almost disorienting honesty. And, on this weekend, it was a reflection of the son who, despite the relative privilege of his birth, still joined the National Guard, still served in Iraq, and passed up the chance both to take his father's Senate seat and to run for governor when political wisdom bade him do it.

American politicians have rarely been held in lower esteem. In some cases, it is well earned. But for Joe Biden, who buried his son, Beau, in Delaware on Saturday, a better measure should apply. Almost alone among senior Washington figures, the US vice-president is liked – and trusted – on all sides. In an era where faith in politicians has vanished, Mr Biden deserves a far better rating. At 72, and with barely 18 months left in office, many see him as a holdover from an age when senators sealed deals with a handshake. But if US politics is to regain its lost pragmatism, his way of business must come back into fashion.